Seriously, though, they're scrubbing the ice in order to control the path of the stone. I think they can either polish it so the stone goes further or roughen it up, so it goes slower. By only scrubbing a bit to the left or the right of the center of the stone you can also make the path curve a little.

Do you know the French game Boules? It's similar to that in a way, only you don't throw or roll the ball but slide a heavy stone.

Hi TinatheConfused, I've been away for a while but can confirm that Dried Frog Pills are the thing for all manner of ills, spills and in one case... wills! I prescribe taking them by the handful as the effects last longer but you do tend to a wont for flying...without means of support.

A while ago Whos Wee Dug sent me a tin to keep my pills in, my Gods!, the top is nearly worn off with my partaking! Cheers Wee Dug!